Hey guys I just bought the MR4 as my first actual marker. Used it yesterday during some cave ball and it worked better than I could imagine. I do want to make some upgrades though.

I'm hoping you guys could help me out. I absolutely HATE the butt stock on the gun and need a longer barrel as well. Anything really that'll improve accuracy and make the marker comfortable to fire. And wondering if its possible to strip the E-trigger off my crap E-bay bought Imagine and use that on the Mr4

Stock:
Cut the top off, that helps a lot and looks cool. Otherwise, theres the adjustable one that Kingman makes, and Trinity makes several styles. Rap4 makes a few overpriced ones that probably aren't in your budget. Anything that fits the MR2 will fit the MR4.

Barrel:
J&J is my favorite, you can get an APEX adapater for them too if thats your thing. CP is also good, they have a tactical style barrel now that might look cool with. If you're on a budget don't bother with Kits.

E-Trigger:
I don't know. I would suspect that you could make it work, but I dunno. You'd have to use the ASA off the Imagine too, as the holes on the older markers weren't the same pattern as the new ones.

Yes, all Spyders use the same barrel thread so any spyder threaded barrel will fit. The MR4 has that shroud on it that the barrel has to go into, so just stay away from those few barrels that are thicker at the base.

The APEX is a barrel made by BT. Its got an adjustable tip which puts backspin on the ball as it leaves the barrel which adds extra range to your shots. The barrel itself isn't so good but you can buy just the tip that puts the spin on the ball and put it onto APEX ready barrels, which lots of companies make now.

Rifled barrels are NOT more accurate than other barrels, thats a myth. Heres link to a video with a lot of good info on barrels!

The truth of the matter is that the gun/barrel doesn't have much to do with accuracy, and its really mostly about the quality of paint. A $30 barrel with $70 paint will outshoot a $150 barrel shooting $30 paint every day. That said, many stock barrels aren't as good as even cheap aftermarket upgrades. Here's some standout barrel companies that I like, they all make great barrels:

Eh... that's false Lawpass. The gun and barrel provide accuracy, and in combination produce more to accuracy than paint alone. If you do not have a good quality barrel and have a marker that will not put out a consistent pressure (and thus velocity) shot to shot, then your balls will be left and right, up and down, too far and too short.

Underboring... not a good idea IMO. Been that way for years, even when the ****in' morons over at TechPB started talking out their asses and claiming it was the best. Get right around the size of the ball, and go out and play. That video also produces some false claims about overboring. Overboring, which I do most of the time with a .694 Freak insert or a .693 Matchstick back, produces less accuracy than a close-to-proper or proper bore fit. Do I care? Not really, it gives me a little challenge when playing with rec players. Would it drive most people nuts? Yeah, probably, which is why I keep a couple full kits on hand for when others borrow my guns. I also have had some experiences in underboring when I was newer in the sport, and didn't know any better. I've had multiple occurrences with a Spyder where the bolt would go forward, and jam on the ball because it wouldn't go into the underbored breech. The ball was bored at ~.689, the breech was .684. This wouldn't be as much of a problem in an EP marker as it has air pressure pushing the bolt back, but in a Spyder it can take you out of the game.

Quality paint is the very last part of the equation. It is almost trickier than the rest, actually, since there are so many different brands out there now. The first step is to find a paintball that your store/field carries consistently, and to try it out. When you first open the box (and make sure there are no breaks prior to purchase, preferably), check the balls. Are they malformed in any way? Dimples? Oblong? If there are minimal dimples and not too many oblong balls, they will perform mostly accurately. The shell is another big thing. Drop it onto concrete or asphalt from shoulder height. Does it break? If so, it's probably pretty brittle. I would say that it would be about right for a Spyder that has a regulator, and about the most brittle I'd go in one. I've had paint that'll drop from my knee and break, and I've shot it out of several different markers and not had a single break in the marker. Those were all soft on paint, though, and not a Spyder or a Tippmann. Spyders and Tippmanns will smack a ball around real nice in the breech purely from design.

What I would recommend to you, RenegadeOfFunk, is to:

Get a regulator so you will be able to get more consistent force (and thus velocity on the ball) and lower your operating pressure.

Get a CP barrel in about the .685-.689 bore range. Balls these days run smaller. In the golden days, all you needed was something in .687-.693.

Find that paint that is consistently in stock locally that works for you.

I would not waste your money on an Apex. I would look at a barrel that does fit an Apex, however, because it will most likely be the right size on the rear's OD for the shroud on your marker.

if you have an ebay account you can get a spyder mr carbine stock on there from a seller I always but my paintball stuff from.for like 20-25 bucks shipped. I had an mr4 with a carbine m4 stock on it and it was amazing

it's a good stock... the only thing I had to buy was a butt stock pad... it adds an inch of cushioning and it's made of rubber... I hated the plastic bumps on the stock... kept digging into me.

The barrel I bought for mine are a 12" Lapco Bigshot barrel with a .687 bore and now I have a 14" Lapco Bigshot barrel with a .689 bore. The 12 inch barrel with Diablo Heats and compressed air and I was shooting on average 280 fps. With the 14" barrel I was shooting 276 fps... I'm assuming that I lost some fps due to the slightly larger bore. Both barrels I bought were around $50 each.

So far these are the barrels I found that would fit the MR4 shroud other than my crappy RAP4 rifled barrel... I tried my JJ ceramic S2 barrel but it wouldn't fit into the shroud. The part after it screws into the gun was a tad too wide. I barrel outer diameter should be around 7/8" I believe.

As far as the E-trigger... I put one on my MR4 and it works great. Fitment was perfect... altho I don't know if there's any difference between that and the imagine e trigger.

If you want to get a front hand grip try this place... they have a nice selection...